1. Field of Invention
The present invention relates to a method of manufacturing a thin film element which uses a technique of transferring the thin film element, such as a functional element, between the substrates, a thin film transistor circuit, an active matrix display device having the thin film transistor circuit, an electro-optical device, and an electronic apparatus.
2. Description of Related Art
In a related art electronic circuit that includes functional elements, such as thin film transistors or organic electroluminescent elements, wiring lines between the functional elements and a supporting substrate, the functional elements can be a part of the entire circuit, and the remaining part of the entire circuit includes wiring lines and a supporting substrate. In a manufacturing process of such an electronic circuit, where the functional elements, wiring lines, and the supporting substrate are manufactured as one body by the same manufacturing process, a highly complicated manufacturing process is required in order to create the functional element having high performance. Accordingly, the manufacturing cost thereof is expensive.
However, it does not require the highly complicated manufacturing process for only the wiring line and the supporting substrate, and the manufacturing cost thereof is also inexpensive. If the functional element is manufactured by a process separated from the process of forming the wiring line and the supporting substrate and is placed only on the required portion of the substrate, the overall manufacturing cost of the electronic circuit may be reduced.
A related art electronic circuit includes functional elements formed on a first substrate, wiring line formed on a second substrate, and element chips including at least one functional element peeled from the first substrate to be transferred onto the second substrate. A thin film transistor circuit in which the functional element in the electronic circuit is the thin film transistor, and an active matrix display device uses the thin film transistor in the thin film transistor circuit as an active matrix device.
According to this method, since the functional element may be placed only on the required portion therein, the overall manufacturing cost of the electronic circuit, the thin film transistor circuit, or the active matrix display device may be reduced. Additionally, as the peeling and transferring process, laser ablation and adhesive can be used (for example, as disclosed in T. Shimoda et al, Techn. Dig. IEDM 1999, 289, S. Utsunomiya et al, Dig. Tech. Pap. SID 2000, 916, T. Shimoda, Proc. Asia Display/IDW '01, 327, S. Utsunomiya et al, Proc. Asia Display/IDW '01, 339).
FIG. 1 shows a peeling and transferring process. A functional element 13 is formed on a first substrate 11 through a peel layer 12. A wiring line 22 and a pad 23 are formed on a second substrate 21. An element chip 14 having at least one functional element 13 is peeled from the first substrate 11 by a laser ablation method in which laser 31 is irradiated to the peel layer 12. An adhesive 32 is previously applied on the second substrate 21, and then the element chip 14 is transferred onto the second substrate 21.
FIG. 2 is a plan view of the element chip. The element chip 14 is rectangular, and is positioned on the first substrate 11.